Lawn sprinkler with filter of plastic foam



June 28, 1 6 J. o. HRUBY, JR

LAWN SPRINKLER WITH FILTER 0F PLASTIC FOAM Filed Aug. 5, 1964 "If/fi m.

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ATTORNEY 3,258,205 LAWN SPRINKLER WITH FILTER F PLASTIC FOAM John 0. Hruby, Jr., Burbank, Calif., 'assiguor to Rain Jet Corporation, Burbank, Califl, a corporation of California Filed Aug. 3, 1964, Ser. No. 387,008 8 Claims. (Cl. 239-204) This invention relates to improvements in lawn sprinldlers.

Conventional lawn sprinklers have relatively narrow outlet orifices to cause the sprayed water to travel an appreciable distance [for covering a substantial area of lawn. A source of annoyance and vexation to an operator of an installed sprinkler system is the occurrence of plugging of the sprinkler orifice or orifices by sand and other solid particles carried by the water supply. A solid particle which has become stuck in an outlet orifice of a sprinkler, though not completely closing the orifice, causes a break in the spray pattern of the sprinkler with the result that a sector of the lawn is not watered. A feature of this invention is the provision in a lawn sprinkler head of a plastic foam filter of interconnecting cell structure which prevents sand and other solid particles from entering the sprinkler orifices where they would otherwise clog the orifices.

Sprinkler heads of the type which include a stem with orifices in the upper end thereof and which are designed to operate in a manner such that the stem extends above the top surface of the body of the sprinkler during a spraying operation, and :then is retracted into the sprinkler body when the water supply is turned off, are often referred to as the pop-up type. They are especially preferred for use in lawns because when not in operation, the stem is protected against damage by traffic over the lawn. The plastic foam element or filter of the improvement provided by this invention serves to retract the stem to its protected position in the sprinkler head when the water supply is turned off.

General objects of this invention are to provide lawn sprinklers having the above mentioned advantageous features and which are simple and rugged in construction, easy to maintain, reliable in operation, and capable of being manufactured at a relatively low cost.

Further objects and advantages of the invention will appear in the following part of this specification wherein .the details of construction and mode of operation of two preferred embodiments are described with reference to the accompanying drawing, in which:

FIG. 1 is a central vertical section through a sprinkler head of this invention shown in its water shutoff position, i.e. with its stem being retracted in the body of the sprinkler;

FIG. 2 is a central vertical section through the sprinkler head with its stem positioned in pop-up water-discharging position;

FIG. 3 is a cross-section through the sprinkler head taken upon a plane indicated by line 33 on FIG. 2;

FIG. 4 is a central vertical section through another sprinkler head of this invention shown in its pop-up position; and

FIG. 5 is a cross-section through the discharge orifice end of the said other sprinkler head taken along line 55 on FIG. 4.

Referring to the drawing in greater detail and with the use of reference numerals, there is shown in FIGS. l-3 a pop-up type sprinkler head of this invention, which is designated generally by reference numeral 10, the same being designed for spraying a half circle sector of lawn area. The sprinkler head is shown secured atop a conventional riser pipe 11 for a lawn sprinkler system.

3,258,295 Patented June 28, 1966 Sprinkler head 10 comprises a hollow body 13 constituted of a cylindrical cup 14 and a cap 15. The cup 14 has a bottom wall 17 integral with a circumferentially continuous side wall 18. The bottom wall 17 has a tapped opening 20 extending axially therethrough for screw-threaded connection with the upper end of the riser 11. The cap 15 comprises a top wall 22 having a circumferentially continuous skirt 23, the inside of which is screwthreaded at 24 for connection of the cap in covering relationship over the top of the side wall 18. The top wall 22 of the body cap 15 has a centrally disposed opening 26. A hollow stem 28 is contained in the sprinkler body 13 with its upper end portion extending slidably into the cap opening 26. The component parts of the stem are a top wall 30, a cylindrical side wall 31 and a bottom plate 32. The inside cavity of the stem is designated by reference numeral 33. At its upper end the stem is provided with an outlet orifice 35, which in the illustrated embodiment is a narrow slit formed in the side wall 31 of the stem proximate the top wall 30. The illustrated slit orifice 35 is not greater than circumfer-entially of the stem whereby the sprinkler 10 forms a fan-shaped spray pattern as for installation of the sprinkler head along an edge of a lawn to cast its spray from the lawn edge and not to spray a marginal strip, as a sidewalk, bordering the lawn.

The inlet for flow of water to the stern cavity 33, for the illustrated embodiment, comprises a plurality of aper tures 38 formed in the cylindrical side wall 31 proximate the lower end of the stem. The bottom plate 32 spans and extends outwardly beyond the lower end of the cylindrical side wall 31. Bottom plate 32 has a circumferentially arranged series of recesses 39 separated by short legs 40 for slidable engagement against the inside surface of the side wall of the cup 15.

The stem is slidable axially in the sprinkler body, i.e. it is movable from its retracted position of FIG. 1 in which the outlet orifice 35 is concealed, to its pop-up position of FIG. 2 in which the outlet orifice is exposed. To prevent rotation of the stem on its longitudinal axis, stop means are provided, here in the form of two longitudinally extending ribs 42 on the inside surface of the cup 14 for slidable engagement by two of the legs 40, respectively, shown in FIG. 3. Another stop means, here in the form of a projection 43 fro-m the inside of the cup 14, serves to limit the extent of upward movement of the stem through engagement of the stop member 43 by the bottom plate 32 when the stem has reached its predetermined pop-up position shown in FIG. 2. The lower end edge of the stop member 43 is spaced from the inside surface of the cap 15 by a distance sufiicient to prevent exposure of the inlet apertures 38 in the elevated position of the stem.

Disposed within the body 13 and arranged circumferentially of the stem is a sleeve 45 of flexible plastic foam having a predominantly open cell structure, i.e. a plastic foam in which the voids or cells thereof are interconnected as in a sponge. Any of the well known plastic foams may be employed as a material from which to form the sleeve 45, e.g. polyurethane, latex foam rubber and vinyl, For sprinkler heads of this invention embodying the popup feature the plastic foam material should be of the flexible variety; however, viewing the invention in a broader aspect, the sprinkler heads need not be of the popup type but may be constructed such that the stern remains in its elevated position of FIG. 2, and in such case the plastic foam material may be of the rigid variety as in the urea and phenolic foams. But whether flexible or rigid, for this invention the cell structure is of the interconnecting type or partly interconnecting type. Being porous, the plastic foam sleeve 45 permits water to pass through it, and as the interstices of the plastic foam mate- 3 rial are relatively small in size, they prevent any sand or other solid particles, entrained in the supply water, from passing into the stem where they would otherwise become wedged in the slit orifice 35.

The plastic foam sleeve 45 is tubular, having an axially extending bore 46 for accommodating the cylindrical side wall 31 of the stem, an upper end surface 48 in abutting relationship against thecap 15, a lower end surface 49 against the bottom plate 32, and an outside surface 50. The outside surface of the plastic foam sleeve 45 is of corrugated configuration, having an axially extending series of uniformly spaced and circumferentially extending depressions or folds 52 which permit the sleeve to be collapsed axially thereof without becoming askew.

In operation, when the control valve (not shown) of the sprinkler system is opened, water passes from the riser 11 to the body cavity 33, exerting pressure against the bottom plate 32 thus to raise the stem 28, and the water passes through the plate openings 39, through the plastic foam sleeve 45, thence through the inlet apertures 38, and thence is sprayed out upon a lawn area through the outlet orifice 35. When the water supply is turned off, the plastic foam sleeve 45 being of flexible plastic foam, urges the stem downwardly to its retracted position shown in FIG. 1. The sleeve 45 may be easily removed from the sprinkler body for purposes of cleaning the filtered sand and the like, merely by unscrewing the cap 15 from the cup portion 14 of the sprinkler body.

Referring to FIGS. 4 and 5, the sprinkler head of this invent-ion illustrated therein is designated generally by reference numeral 55 and is generally similar in structure to the sprinkler head 10 of FIGS. l3. The component parts of the sprinkler head 55 which are substantially identical to their corresponding parts in sprinkler head 10 are designated by the same reference numerals, respectively, for the parts of head 10, but are primed in the case of head 55.

One respect in which sprinkler head 55 differs from head 10 of FIGS. 1-3, is that the stem 28' of head 55 has four outlet orifices arranged in a circumferentially extending series with the adjacent orifices overlapping each other so that the sprinkler will produce a complete circular spray pattern.

Another feature of the sprinkler head 55 of FIGS. 4 and 5, differing from head 10 of FIGS. 1-3, is that a coil spring 57 is provided around the cylindrical side wall of stem 28' to assist in retracting the stem when the water supply is turned off. The axially extending bore 46' of the sleeve is of larger cross-section than that of the sleeve bore 45 in head 10. The coil spring 57 and the enlarged axial bore of the sleeve 42' prevent bulging of the sleeve 45' into the inlet openings 38' of the stem. Sprinkler head does not include .any stop means such as shown at 42 in FIG. 3, for preventing rotation of the stem on its longitudinal axis as rotation, if any, would be inconsequential because the spray pattern of the head 55 is a complete circle. The coil spring 57 makes unnecessary any further stop means such as that shown at 43 in FIGS. 1 and 2 inasmuch as the spring 57 resiliently limits the extent of upward movement of the stem 28'.

While the instant invention has been shown and described herein, in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims.

What I claim is:

1. A sprinkler comprising a hollow body having a water inlet opening adapted to be connected atop a water supply pipe, a hollow stem having a lower portion extending into the body and the stem having an upper portion which at least when the sprinkler is in operation extends upwardly of the body, the stem having an inlet aperture in said lower portion, the stem having an outlet orifice in said upper portion for casting a spray of water outwardly from the stem, and a plastic foam sponge covering said inlet aperture for preventing entry of solid particles carried in the water supply from becoming stuck in said outlet orifice.

2. A sprinkler comprising a hollow body having a cup and a removable cap, the cup having a water inlet opening for connection to a water supply pipe, the cap having an opening, a hollow stem having a lower portion extending into the body and the stem having an upper portion which at least when the stem is in operation extends upwardly through said cap opening, the stem having an inlet aperture in said lower portion, the stem having an outlet orifice in said upper portion for casting a spray of water outwardly from the stem, and a sleeve of plastic foam sponge encircling said lower portion to filter solid particles carried in the water supply from entering said inlet aperture, thereby to prevent said particles from becoming stuck in said outlet orifice.

3. A sprinkler according to claim 2 and comprising a coil spring axially disposed within said sleeve and en circling said lower portion thereby to retain said sleeve against bulging into said inlet aperture.

4. A pop-up type lawn sprinkler comprising a hollow body having a cup and a removable cap, the cup having a bottom wall having a water inlet opening adapted to be connected atop a Water supply pipe, the cap having an opening, a hollow stem having a cylindrical side wall slidable axially in said cap opening, said side wall having an inlet aperture adjacent the lower end of the stem, the stem having an outlet orifice adjacent the upper end of the stem, means for limiting upward movement of the stem to a position in which said inlet aperture is disposed within said body, a cylindrical sleeve of flexible plastic foam material having an interconnected cell structure and being disposed in the body and encircling said stem and covering said inlet aperture, and an annular member secured around said side wall below said inlet aperture for abutment against the lower end of said sleeve, said member defining a passageway for flow of water from said water inlet open-ing to circumferentially of said sleeve, whereby the sleeve filters water passing through the sprinkler.

5. A lawn sprinkler according to claim 4 in which said orifice is a horizontally extending slit only part way around the said side wall of the stem, and stop means in the body engageable with said member for preventing rotation of the stem on its longitudinal axis in the body.

6. A lawn sprinkler according to claim 4 in which the outside surface of said sleeve has an axially extending series of circumferentially extending folds to permit axial collapsing of the sleeve without the sleeve becoming askew.

7. A lawn sprinkler according to claim 4 in which said limiting means comprises a projection on the inside of said cup engageable with said annular member.

8. A lawn sprinkler according to claim 4 in which said limiting means comprises a coil spring axially disposed within said sleeve and encircling said side wall of the stern and in engagement at one end with the inside surface of said cap and at its other end with said annular member.

References Cited by the Examiner UNITED STATES PATENTS 2,546,574 3/1951 Wilcox 239-204 2,909,325 10/1959 Hunter 239205.

EVERETT W. KIRBY, Primary Examiner. 

1. A SPRINKLER COMPRISING A HOLLOW BODY HAVING A WATER INLET OPENING ADAPTED TO BE CONNECTED ATOP A WATER SUPPLY PIPE, A HOLLOW STEM HAVING A LOWER PORTION EXTENDING INTO A BODY AND THE STEM HAVING AN UPPER PORTION WHICH AT LEAST WHEN THE SPRINKLER IS IN OPERATION EXTENDS UPWARDLY OF THE BODY, THE STEM HAVING AN INLET APERTURE IN SAID LOWER PORTION, THE STEM HAVING AN OUTLET ORIFICE IN SAID UPPER PORTION FOR CASTING A SPRAY OF WATER OUTWARDLY FROM THE STEM AND A PLASTIC FOAM SPONGE COVERING SAID 